If a bad situation is acute, it causes severe problems or damage.

She felt acute embarrassment/anxiety/concern at his behaviour. 她对他的行为感到极其尴尬／忧虑／担忧。

The problem of poverty is particularly acute in rural areas. 贫困问题在农村地区尤为严重。

An acute pain or illness is one that quickly becomes very severe.

acute abdominal pains 剧烈腹痛

an acute attack of appendicitis 阑尾炎急性发作

Compare: chronic (LONG-LASTING)

used to describe intelligence, senses, etc. that are very good, accurate, and able to notice very small differences

acute eyesight/hearing 敏锐的视觉／听觉

an acute sense of smell 灵敏的嗅觉

a woman of acute intelligence/judgment 机敏聪颖／有敏锐判断力的女性

An acute angle is less than 90 degrees.

Compare: obtuse (ANGLE) reflex

a sign that is written above a letter in some languages, showing you how to pronounce the letter

There's an acute accent on the e in "café". Café这个词中字母e上面有个尖音符号。